I really wouldn't worry about the feeding to sleep at this age. They grow out of it when they're ready to, and forcing them possibly does more harm than good. Gently nudging I wouldn't worry about, so by all means try patting to sleep, putting down awake first, but don't withold milk and start a battle about it just for the sake of it. They're just not capable of understanding it.
DS fed to sleep until about 5 months, then took a two month break where he'd unlatch, roll over and fall asleep. Then he suddenly wanted to feed to sleep again. If they need the reassurance, why not give it? He gradually stopped again at just over a year, all by himself. Tbh it was a godsend to know that I could feed him to sleep without any problems. Travelling, on a plane, out for the day, visiting other people, hotels, strange beds, etc etc... I wish I still had that option sometimes (4 hour plane ride I'm looking at you).
There are many growth spurts around this age too, so definitely don't limit night time feeds to 6 hours. Several experts don't recommend night weaning till they hit a year, as babies can still physically need to feed at night until then. Obviously not all do, but very, very many do.
One study found that only 16% of babies slept through at 6 months... It is perfectly normal and acceptable for them to wake more often and feed when they're little. Tough though ;)
Let me know if you'd like some links to read.